Infiltrant for dental application

ABSTRACT

The invention provides an infiltrant for dental application that comprises crosslinking monomers. In accordance with the invention the infiltrant has a penetration coefficient PC&gt;50 cm/s, and comprises 0.05%-20% by weight of acid-group-containing monomers.

This application is a Continuation of U.S. application Ser. No.12/714,942, filed Mar. 1, 2010, which is incorporated herein byreference and which claims priority to European Patent ApplicationNumber 09003321.8, filed Mar. 6, 2009.

The invention relates to an infiltrant for dental application thatcomprises crosslinking monomers and also to its use in treating and/orpreventing carious enamel lesions.

Carious enamel lesions here are essentially instances of carious damagethat extend in the dental enamel but have not yet led to cavitation(hole formation). Carious enamel lesions are demineralized regions ofthe dental enamel that may have a depth of up to about 2-3 mm.

The published international application WO 2007/131725A1 has disclosedtreating carious enamel lesions by an infiltration method andinfiltrants, to prevent cavitation and obviate the restoration withdental composites that is otherwise typically practiced. In theinfiltration method, after any superficial remineralized layer presenthas been removed, the lesion is contacted with an infiltrant that iscomposed substantially of monomers, which then infiltrate. When theinfiltrant has infiltrated the lesion, the monomers 30 are polymerizedby means of photoactivation. This seals the lesion. The progression ofthe caries is halted.

Infiltration requires specific monomers or monomer mixtures, since knowndental adhesion promoters, dental adhesives or dental lacquers (alsoknown as primers, bondings or sealants) penetrate too slowly and/orinadequately into the lesion and/or infiltrate the lesion completelyand/or do not cure (polymerize) completely and/or quickly. WO2007/131725 A1 describes the use of monomers or monomer mixtures wherebythe infiltrant has a penetration coefficient PC>50.

Disadvantageous features of the infiltrants described therein are theircuring properties, more particularly the depth of through-cure, and alsothe mechanical properties of the polymerized infiltrant, moreparticularly the strength of the bond with the tooth substance such as,for example, the enamel, and the stress cracking stability.

The invention is based on the object of providing an infiltrant of thetype specified at the outset that has improved curing properties and agood sealing effect and is also long-lived.

The infiltrant of the invention has a penetration coefficient PC>50cm/s, and comprises 0.05%-20% by weight of acid-group-containingmonomers.

First of ail a number of terms used in the context of the invention willbe elucidated. The term “infiltrant” refers to a liquid which as anuncured resin is able to penetrate into an enamel lesion (a poroussolid). Following penetration, the infiltrant can be cured therein.

Crosslinking monomers have two or more polymerizable groups and aretherefore able to crosslink polymerized chains with one another in apolymerization.

The penetration of a liquid (uncured resin) into a porous solid (enamellesion) is described physically by the Washburn equation (equation 1,see below). In this equation it is assumed that the porous solidrepresents a bundle of open capillaries (Buckton G., Interfacialphenomena in drug delivery and targeting. Chur, 1995); in this case, thepenetration of the liquid is driven by capillary forces.

$\begin{matrix}{d^{2} = {\left( \frac{{\gamma \cdot \cos}\; \theta}{2\eta} \right){r \cdot t}}} & {{equation}\mspace{14mu} 1}\end{matrix}$

-   d distance by which the liquid resin moves-   γ surface tension of the liquid resin (with respect to air)-   θ contact angle of liquid resin (with respect to enamel)-   η dynamic viscosity of the liquid resin-   r capillary radius (pore radius)-   t penetration time

The expression in parentheses in the Washburn equation is referred to asthe penetration coefficient (PC, equation 2, see below) (Fan P. L. etal. , Penetrativity of sealants. J. Dent. Res., 1975, 54: 262-264). ThePC is composed of the surface, tension of the liquid with respect to air(γ), the cosine of the contact angle of the liquid with respect toenamel (θ), and the dynamic viscosity of the liquid (η). The greater thevalue of the coefficient, the faster the penetration of the liquid intoa given capillary or into a given porous bed. This means that a highvalue of PC can be obtained through high surface tensions, lowviscosities, and low contact angles, the influence of the contact anglebeing comparatively small.

$\begin{matrix}{{PC} = \left( \frac{{\gamma \cdot \cos}\; \theta}{2\eta} \right)} & {{equation}\mspace{14mu} 2}\end{matrix}$

-   PC penetration coefficient-   γ surface tension of the liquid resin (with respect to air)-   θ contact angle of liquid resin (with respect to enamel)-   η dynamic viscosity of the liquid resin

Infiltrants are frequently applied in difficult-to-access interdentalspaces (approximally). Particularly when using light-curing systems,optimum irradiation to accomplish full curing in interdental spaces isdifficult. The invention has recognized that, through the use of acomposition, as defined in claim 1, it is possible to achieve asufficient depth of through-cure even under the stated difficultconditions, and also that a sufficiently high penetration coefficientcan be retained, ensuring a sufficient depth of penetration of theresin. The inventive composition of the infiltrant therefore produceshigh penetrativity in combination with effective full curability evenunder the difficult conditions of approximal application.

The penetration coefficient of the infiltrant is preferably above 100cm/s, but may also be above 150 or above 200 cm/s.

The inventively envisaged addition of acid-group-containing monomers notonly increases the through-cured depth but also improves the adhesion tothe tooth material such as tooth enamel, for example. Moreover, theoverall amount of crosslinking monomers, especially monomers containingmore than two polymerizable groups, can be lowered, leading to improvedstress cracking stability. The inventive addition of theacid-group-containing monomers further enhances the durable sealing ofthe lesion. The barrier effect with respect to diffusion of lowmolecular mass nutrients, exemplified by carbohydrates (sugars), isfurther increased. The amount of acid-group-containing monomers ispreferably 0.1% to 15%, more preferably 0.2% to 10%, more preferably0.5% and 5%, more preferably 0.5% to 2% by weight.

Suitable acid groups are for example, carboxylic and sulfonic acidgroups. Preferred acid groups in the acid-group-containing monomers arephosphoric and/or phosphonic acid groups. Examples include correspondingorganic hydrogenphosphates or dihydrogenphosphates.

The acid-group-containing monomers may be of crosslinkingconstruction—that is, may, in addition to the acid group, contain two ormore polymerizable groups, examples then being monomers of the formula

R¹[X_(k)R² _(l)Y_(m)]_(n).

In selected applications it may be advantageous if they contain only onepolymerizable group. The acid-group-containing monomers may moreparticularly be acrylates or methacrylates, acrylamides ormethacrylamides.

For example, they may be acrylates or methacrylates which are listedlater on below as preferred additional monomers having a polymerizablegroup, which also have a corresponding acid group.

In accordance with the invention the acid-group-containing monomerspreferably have a molecular weight (weight average) of 100-1000 g/mol.The acid-group-containing monomers are preferably soluble in thenonaqueous resin mixtures of the infiltrant. The term “nonaqueous” heredenotes preferably resin mixtures which contain less than 5% by weight,preferably less than 2% by weight, of water.

Acid-group-containing monomers which can be used with preference are,for example, 4-methacryloyloxyethyl-trimellitic acid (4-MET),methacryloyloxydecylmalonic acid (MAC-10), maleic acid mono-HEMA ester,N-methacryloyl-N′,N′-dicarboxymethyl-1,4-diaminobenzene,N-2-hydroxy-3-methacryloyloxypropyl-N-phenylglycine,O-methacryloyltyrosinamide, 4-methacryloylaminosalicylic acid, phenylmethacryloyloxyalkylphosphates, e.g., phenyl methacryloyloxyethylphosphate (phenyl-P), methacryloyloxyalkyl dihydrogenphosphates, e.g.,methacryloyloxyethyl dihydrogenphosphate (HEMA-P), methacryloyloxypropyldihydrogenphosphate (MPP), methacryloyloxyhexyl dihydrogenphosphate(MHP), methacryloyloxydecyl dihydrogenphosphate (MDP), glyceryldimethacrylate phosphate (GPDM), pentaerythritol triacrylate phosphate(PENTA-P), bis(hydroxyethylmethacrylate) phosphate,(meth)acrylamidophosphates, (meth)acrylamidodiphosphates,(meth)acrylamidoalkyl phosphonates, (meth)acrylamidoalkyldiphosphonates, bismethacrylamidoalkyl dihydrogenphosphates,vinylbenzylphosphonic acid, and vinylbenzoic acid.

Among the stated methacryloyloxyalkyl dihydrogenphosphates, particularpreference is given to methacryloyloxydecyl dihydrogenphosphate (MDP).

The infiltrants of the invention may be cured free-radically,anionically or cationically, depending on the chemical structure of themonomers they comprise. Preferably the monomers are curablefree-radically or cationically.

The free-radical curing of the monomers of the invention can beaccomplished by vinyl polymerization of suitable double bonds.Particularly suitable in this respect are (meth)acrylates,(meth)acrylamides, as disclosed in, for example, EP 1674066 A1 and EP1974712 A1, styryl compounds, cyanoacrylates, and compounds havingsimilarly effectively free-radically polymerizable double bonds. Afurther possibility of free-radical curing lies in the ring-openingpolymerization of cyclic vinyl compounds such as the vinylcyclopropanesdescribed in EP1413569, EP1741419, and EP1688125, or other cyclicsystems such as vinylidene-substituted orthospiro carbonates ororthospiro esters. Another possibility also lies in the copolymerizationof the ring-opening polymerizing systems with the aforementioned simplypolymerizing double bonds.

Free-radical curing may also be accomplished, furthermore, by a stagereaction known under the rubric of the thiol-ene reaction, as describedin WO 2005/086911.

The cationic curing of the monomers of the invention may likewise beaccomplished by both ring-opening polymerization and vinylpolymerization. Suitable vinyl polymers are vinyl ethers, styrylcompounds, and other compounds having electron-rich vinyl groups.Suitable ring-openingly polymerizing monomers are compounds which carryepoxide, oxetane, aziridine, oxazoline or dioxolane groups. Furtherring-openingly polymerizing groups may be taken from the literature, forexample: K. J. Ivin, T. Saegusa, (eds.), Vol. 2, Elsevier Appl. Sci.Publ., London 1984). Particularly suitable are silicon-containingepoxide monomers, as described in WO 02/066535 or WO 2005/121200.Particularly advantageous in the context of the use of epoxides oroxetanes is the low polymerization contraction and also the lowinhibition layer of these materials.

The fraction of crosslinking monomers having two polymerizable groupscan be 99.8% to 50%, preferably 99.5% to 60%, more preferably 99% to60%, more preferably 99% to 70% by weight.

The crosslinking monomers having two polymerizable groups are preferablyderivatives of acrylic and/or methacrylic acid. They may preferably beselected from the group consisting of allyl methacrylate; allylacrylate; PRDMA, 1,3-propanediol dimethacrylate; BDMA, 1,3-butanedioldimethacrylate; BDDMA, 1,4-butanediol dimethacrylate; PDDMA,1,5-pentanediol dimethacrylate; NPGDMA, neopentyl glycol dimethacrylate;HDDMA, 1,6-hexanediol dimethacrylate; NDDMA, 1,9-nonanedioldimethacrylate; DDDMA, 1,10-decanediol dimethacrylate; DDDDMA,1,12-dodecanediol dimethacrylate; PRDA, 1,3-propanediol diacrylate; BDA,1,3-butanediol diacrylate; BDDA, 1,4-butanediol diacrylate; PDDA,1,5-pentanediol diacrylate; NPGDA, neopentyl glycol diacrylate; HDDA,1,6-hexanediol diacrylate; NDDA, 1,9-nonanediol diacrylate; DDDA,1,10-decanediol diacrylate; DDDDA, 1,12-dodecanediol dimethacrylate;EGDMA, ethylene glycol dimethacrylate; DEGDMA, diethylene glycoldimethacrylate; TEDMA, triethylene glycol dimethacrylate; TEGDMA,tetraethylene glycol dimethacrylate; EGDA, ethylene glycol diacrylate;DEGDA, diethylene glycol diacrylate; TEDA, triethylene glycoldiacrylate; TEGDA, tetraethylene glycol diacrylate; PEG200DMA,polyethylene glycol 200 dimethacrylate; PEG300DMA, polyethylene glycol300 dimethacrylate; PEG400DMA, polyethylene glycol 400 dimethacrylate;PEG600DMA, polyethylene glycol 600 dimethacrylate; PEG200DA,polyethylene glycol 200 diacrylate; PEG300DA, polyethylene glycol 300diacrylate; PEG400DA, polyethylene glycol 400 diacrylate; PEG600DA,polyethylene glycol 600 diacrylate; PPGDMA, polypropylene glycoldimethacrylate; PPGDA, polypropylene glycol diacrylate; NPG(PO)2DMA,propoxylated (2) neopentyl glycol dimethacrylate; NPG(PO)2DA,propoxylated (2) neopentyl glycol diacrylate; bis-MA, bisphenol Adimethacrylate; bis-GMA, bisphenol A glycerol dimethacrylate;BPA(EO)DMA, ethoxylated bisphenol A dimethacrylate (EO=1-30);BPA(PO)DMA, propoxylated bisphenol A dimethacrylate (PO=1-30);BPA(EO)DA, ethoxylated bisphenol A diacrylate (EO=1-30); BPA(PO)DA,propoxylated bisphenol A diacrylate (PO=1-30); BPA(PO)GDA, propoxylatedbisphenol A glycerol diacrylate; UDMA, diurethane dimethacrylate;TCDDMA, tricyclo[5.2.1.0]decanedimethanol dimethacrylates; TCDDA,tricyclo[5.2.1.0]-decanedimethanol diacrylates; EBA,N,N′-ethylenebis-acrylamide; DHEBA,N,N′-(1,2-dihydroxyethylene)bisacrylamide; DEPBA,N,N′-diethyl(1,3-propylene)bisacrylamide; TMHMBMA,N,N′-(2,2,4-trimethylhexamethylene)bismethacrylamide; andbis[2-(2-methylacrylamino)ethoxycarbonyl]hexamethylenediamine.

The proportion of crosslinking monomers having at least threepolymerizable groups can preferably be between 0% and 50%, morepreferably 10% and 30% by weight.

Preferred crosslinking monomers having at least three polymerizablegroups have the following formula

R¹[X_(k)R² _(l)Y_(m)]_(n)

with the following definitions:

R¹ is a linear or branched hydrocarbon having 3-24 C atoms, comprisingalkyl, cycloalkyl or aryl;

optionally containing O, N, Si, S, P as heteroatoms, examples beingsiloxane and/or cyclosiloxane and/or carbosilane and/or cyclocarbosilaneand/or, in particular, ether groups or polyether groups, polyestergroups, polysiloxane groups or polycarbosilane groups;

optionally substituted by hydroxyl and/or carbonyl and/or halogen(preferably fluorine) and/or ammonium-alkylene groups and/or siloxaneand/or cyclosiloxane and/or carbosilane and/or cyclocarbosilane;

R² is a linear or branched hydrocarbon having 1-16 C atoms, comprisingalkyl, cycloalkyl or aryl;

optionally containing O, N, Si, S, P as heteroatoms, examples beingsiloxane and/or cyclosiloxane and/or carbosilane and/or cyclocarbosilaneand/or, in particular, ether groups or polyether groups, polyestergroups, polysiloxane groups or polycarbosilane groups;

optionally substituted by hydroxyl and/or carbonyl and/or halogen(preferably fluorine) and/or ammonium-alkylene groups and/or siloxaneand/or cyclosiloxane and/or carbosilane and/or cyclocarbosilane;

X is a linking group identically or differently selected from an ethergroup, carbonyl group, ester group, amide group, urethane group or ureagroup;

Y is a group identically or differently comprising a polymerizabledouble bond and/or a ring-openingly polymerizable group and/or a thiolgroup and/or an epoxide group and/or a vinyl, preferably (meth) acrylateand/or (meth)acrylamide;

k is 0 or 1;

l is 0 or 1;

m is at least 1;

n is at least 1; and

m×n is at least 3.

It may be of advantage if the monomers have additional functional groupssuch as ammonium-alkylene groups or halogen, especially fluorinatedalkylene.

Suitable low-viscosity monomers having at least three polymerizablegroups are, for example, glycerol triacrylate, TMPTMA,trimethylolpropane trimethacrylate; TMPTA, trimethylolpropanetri(meth)acrylate; DTMPTA, ditrimethylolpropane tetra(meth)acrylate;diPENTA, dipentaerythritol penta(meth)acrylate; or DPEHA,dipentaerythritol hexa(meth)acrylate.

Preferred low-viscosity monomers having at least three polymerizablegroups are based for example on alkoxylated multiple alcohols (tri-,tetra-, penta-, hexa-, polyols) such as trimethylolpropane,ditrimethylolpropane, glycerol, pentaerythritol or dipentaerythritol.

Particularly preferred are (meth)acrylic esters of alkoxylated multiplealcohols such as, for example, ethoxylated glycerol triacrylate,propoxylated glycerol triacrylate, ethoxylated trimethylolpropanetrimethacrylate, ethoxylated trimethylolpropane triacrylate,propoxylated trimethylolpropane trimethacrylate, propoxylatedtrimethylolpropane triacrylate, ethoxylated pentaerythritoltrimethacrylate, ethoxylated pentaerythritol triacrylate, ethoxylatedpentaerythritol tetramethacrylate, ethoxylated pentaerythritoltetraacrylate, ethoxylated dipentaerythritol trimethacrylate,ethoxylated dipentaerythritol tetramethacrylate, ethoxylateddipentaerythritol pentamethacrylate, ethoxylated dipentaerythritolhexamethacrylate, ethoxylated dipentaerythritol triacrylate, ethoxylateddipentaerythritol tetraacrylate, ethoxylated dipentaerythritolpentaacrylate, ethoxylated dipentaerythritol hexaacrylate, propoxylatedpentaerythritol trimethacrylate, propoxylated pentaerythritoltriacrylate, propoxylated pentaerythritol tetramethacrylate,propoxylated pentaerythritol tetraacrylate, propoxylateddipentaerythritol trimethacrylate, propoxylated dipentaerythritoltetramethacrylate, propoxylated dipentaerythritol pentamethacrylate,propoxylated dipentaerythritol hexamethacrylate, propoxylateddipentaerythritol triacrylate, propoxylated dipentaerythritoltetraacrylate, propoxylated dipentaerythritol pentaacrylate andpropoxylated dipentaerythritol hexaacrylate.

Those alkoxy groups attached to the alcohols represent (molecular-)chainextenders. Chain extension may be achieved preferably throughethoxylation or propoxylation. For chain extension there are furtherlinking possibilities available, examples being ether bonds, esterbonds, amide bonds, urethane bonds, and the like, which may be followedin turn preferably by ethylene glycol groups or propylene glycol groups.

Preferred chain extenders are for example

—CH₂—CH₂—

—CH₂—CH₂—CH₂—

—CH₂—CH₂—O—CH₂—CH₂—

—CH₂—CH₂—CH₂—O—CH₂—CH₂—CH₂—

and so on

—O—CH₂—CH₂—

—O—CH₂—CH₂—CH₂—

—O—CH₂—CH₂—O—CH₂—CH₂—

—O—CH₂—CH₂—CH₂—O—CH₂—CH₂—CH₂—

and so on

—O—CO—CH₂—CH₂—

—O—CO—CH₂—CH₂—CH₂—

—O—CO—CH₂—CH₂—O—CH₂—CH₂—

—O—CO—CH₂—CH₂—CH₂—O—CH₂—CH₂—CH₂—

and so on

—CO—CH₂—CH₂—

—CO—CH₂—CH₂—CH₂—

—CO—CH₂—CH₂—O—CH₂—CH₂—

—CO—CH₂—CH₂—CH₂—O—CH₂—CH₂—CH₂—

and so on

—NR³—CO—CH₂—CH₂—

—NR³—CO—CH₂—CH₂—CH₂—

—NR³—CO—CH₂—CH₂—O—CH₂—CH₂—

—NR³—CO—CH₂—CH₂—CH₂—O—CH₂—CH₂—CH₂—

and s o on

—O—CO—NR³—CH₂—CH₂—

—O—CO—NR³—CH₂—CH₂—CH₂—

—O—CO—NR³—CH₂—CH₂—O—CH₂—CH₂—

—O—CO—NR³—CH₂—CH₂—CH₂—O—CH₂—CH₂—CH₂—

and so on

—NR³—CO—O—CH₂—CH₂—

—NR³—CO—O—CH₂—CH₂—CH₂—

—NR³—CO—O—CH₂—CH₂O—CH₂—CH₂—

—NR³—CO—O—CH₂—CH₂—CH₂—O—CH₂—CH₂—CH₂—

and so on

—NR³—CO—NR³—CH₂—CH₂—

—NR³—CO—NR³—CH₂—CH₂—CH₂—

—NR³—CO—NR³—CH₂—CH₂—O—CH₂—CH₂—

—NR³—CO—NR³—CH₂—CH₂—CH₂—O—CH₂—CH₂—CH₂—

and so on

where R³ is H or an alkyl group, preferably a methyl group.

The chain-extending group is functionalized preferably terminally withthe crosslinking groups, preferably with a methacrylate or an acrylategroup, a methacrylamide or acrylamide group.

A crosslinking point is regarded as being the position of thecrosslinking polymerizable group—for example, the position of a C═Cdouble bona in the monomer.

The chain length is preferably such that the distance betweencrosslinking points is at least 7, preferably at least 9, morepreferably 10 to 30, with particular preference 11 to 21 bond lengths.The distance is preferably less than 5 0 bond lengths.

By distance between crosslinking points is meant the shortest distancebetween the crosslinking groups, as for example two C═C double bonds,along the molecule. The reference is therefore only to the constitutionof the molecule, and not, say, to the actual spatial position of thegroups relative to one another, as governed, for instance, byconfiguration or conformation.

By bond length is meant the distance between two atoms in the molecule,irrespective of the nature of the covalent bonding and of the exactlength of the individual covalent bond.

The fraction of crosslinking monomers having at least threepolymerizable groups and a distance between crosslinking points of lessthan 10 bond lengths, based on the total mass of the monomers, ispreferably less than 20% by weight, more preferably less than 10% byweight, more preferably less than 5% by weight.

By setting a distance between the crosslinking groups, as defined above,and, consequently, by setting a corresponding network arc length incrosslinked polymers, the stresses in the cured polymer can be reduced.This reduction in stresses means that, even under temperaturefluctuation loads such as, for example, thermal cycling between 5 and55° C., which is used as a test method, there are no instances ofstress-induced cracking in the polymer. The mechanical properties andespecially the long-term stability of the cured infiltrant are improvedin this way.

The preferred fraction of these monomers is dependent on the number ofcrosslinking groups in the monomer mixture, on the size of thechain-extending groups, and on the resultant PC.

The infiltrant of the invention may further comprise monomers having onepolymerizable group. These monomers may preferably be selected from thegroup consisting of MMA, methyl methacrylate; EMA, ethyl methacrylate;n-BMA, n-butyl methacrylate; IBMA, isobutyl methacrylate, t-BMA,tert-butyl methacrylate; EHMA, 2-ethylhexyl methacrylate, LMA, laurylmethacrylate; TDMA, tridecyl methacrylate; SMA, stearyl methacrylate;CHMA, cyclohexyl methacrylate; BZMA, benzyl methacrylate, IBXMA,isobornyl methacrylates; HEMA, 2-hydroxyethyl methacrylate; HPMA,2-hydroxypropyl methacrylate; DMMA, dimethylaminoethyl methacrylate;DEMA, diethylaminoethyl methacrylate; GMA, glycidyl methacrylate; THFMA,tetrahydrofurfuryl methacrylate; AMA, allyl methacrylate; ETMA,ethoxyethyl methacrylate; 3FM, trifluoroethyl methacrylate; 8FM,octafluoropentyl methacrylate; AIB, isobutyl acrylate; TBA, tert-butylacrylate; LA, lauryl acryate; CEA, cetyl acrylate; STA, stearylacrylate; CHA, cyclohexyl acrylate; BZA, benzyl acrylate; IBXA,isobornyl acrylate; 2-MTA, 2-methoxyethyl acrylate; ETA, 2-ethoxyethylacrylate; EETA, ethoxyethoxyethyl acrylate; PEA, 2-phenoxyethylacrylate; THFA, tetrahydrofurfuryl acrylate; HEA, 2-hydroxyethylacrylate; HPA, 2-hydroxypropyl acrylate; 4HBA, 4-hydroxybutyl acrylate;DMA, dimethylaminoethyl acrylate; 3F, trifluoroethyl acrylate; 17F,heptadecafluorodecyl acrylate, 2-PEA, 2-phenoxyethyl acrylate; TBCH,4-tert-butylcyclohexyl acrylate; DCPA, dihydrodicyclopentadienylacrylate; EHA, 2-ethylhexyl acrylate; and 3EGMA, triethylene glycolmono-methacrylate.

The monomers, monomer mixtures and/or infiltrants preferably have adynamic viscosity of less than 50 mPas, more preferably less than 30mPas, with particular preference less than 20 mPas.

The mixing of different monomers serves in particular to fine-tune themechanical properties such as hardness and strength, the depth ofthrough-cure and/or the degree of polymerization, the residual monomercontent, the extent of the lubricating layer, the contraction, thestability, the water absorption, and, in particular, the freedom fromstress with retention of a high penetrativity (PC>50).

Also important in particular is the water compatibility of the monomers,in the case, for instance, where the enamel lesion still containsresidual moisture after preparation (etching, rinsing, drying). Certainmonomers may absorb residual moisture and so further improvepenetration. Suitability for this purpose is possessed in particular bywater-soluble and/or phase-mediating esters of (meth)acrylic acid, e.g.,HEMA, 2-hydroxyethyl methacrylate, or GDMA, glycerol dimethacrylate, orGMA, glycerol monomethacrylate.

Mixing with further monomers may also serve in particular to fine-tuneother advantageous properties such as high surface smoothness(plaque-preventing), fluoride release, X-ray opacity, adhesion toenamel, long-term color stability, biocompatibility, and so on.

The infiltrant may also comprise hyperbranched monomer's, dendrimers forexample, that are familiar in the dental sector and are known to theskilled worker from, for example, WO 02/062901, WO 2006/031972 or EP1714633, especially in order to lower the residual monomer content andto enhance the biocompatibility.

The infiltrant may comprise bactericidal monomers that are customary inthe dental sector and are known to the skilled worker from, for example,EP 1285947 or EP 1849450.

The monomer mixtures and the infiltrant have a PC>50, preferably >100,more preferably >200.

The infiltrant comprises agents for curing the infiltrant. The agent forcuring may be initiators that are customary in the dental sector and areknown to the skilled worker, more particularly light-activated initiatorsystems, or else may be chemically activating initiators, or mixtures ofthe different systems.

The initiators that can be used here may be, for example,photoinitiators. These are characterized in that they are able, throughabsorption of light in the wavelength range from 300 nm to 700 nm,preferably from 350 nm to 600 nm, and more preferably from 380 nm to 500nm, and, optionally, through additional reaction with one or morecoinitiators, to effect curing of the material. Preference is given hereto using phosphine oxides, benzoin ethers, benzil ketals, acetophenones,benzophenones, thioxanthones, bisimidazoles, metallocenes, fluorones,α-dicarbonyl compounds, aryldiazonium salts, arylsulphonium salts,aryliodonium salts, ferrocenium salts, phenylphosphonium salts or amixture of these compounds.

Particular preference is given to usingdiphenyl-2,4,6-trimethylbenzoylphosphine oxide, benzoin, benzoin alkylethers, benzil dialkyl ketals, α-hydroxyacetophenone,dialkoxyacetophenones, α-aminoacetophenones, isopropylthioxanthone,camphorquinone, phenylpropanedione, 5,7-diiodo-3-butoxy-6-fluorone,(eta-6-cumene) (eta-5-cyclopentadienyl)iron hexafluorophosphate,(eta-6-cumene)-(eta-5-cyclopentadienyl)iron tetrafluoroborate,(eta-6-cumene) (eta-5-cyclopentadienyl)iron hexafluoroantimonate,substituted diaryliodonium salts, triarylsulphonium salts or a mixtureof these compounds.

Coinitiators used for photochemical curing are preferably tertiaryamines, borates, organic phosphites, diaryliodonium compounds,thioxanthones, xanthenes, fluorenes, fluorones, α-dicarbonyl compounds,fused polyaromatics or a mixture of these compounds. Particularpreference is given to using N,N-dimethyl-p-toluolidine,N,N-dialkylalkylanilines, N,N-dihyhdroxyethyl-p-toluidine, 2-ethylhexylp-(dimethyl-amino)benzoate, butyrylcholine triphenylbutylborate,N,N-dimethyl-4-tert-butylaniline, N,N-diethyl-3,5-di-tert-butylaniline,4-tert-butylaniline or a mixture of these compounds.

To 100 parts of resin or resin mixture it is preferred to add 0.05 to 2parts of photoinitiator, more preferably 0.1 to 1 part. The coinitiatoris present in excess, 1-5 times, preferably 1-3 times, relative to theinitiator.

The infiltrant can be prepared from a kit having at least twocomponents. Infiltrants comprising two components have the advantagethat they can be formulated so as to be self-curing (chemical curing).In one embodiment a first component comprises monomers and chemicallyactivable initiators and a second component comprises suitableactivators.

For chemical curing at room temperature it is general practice to use aredox initiator system composed of one or more initiators and one ormore coinitiators with activator function. For reasons of storagestability, initiator and/or initiators and coinitiator and/orcoinitiators are incorporated into parts of the infiltrant of theinvention that are spatially separate from one another, i.e., thematerial is a multicomponent material, preferably a two-componentmaterial. Initiator or initiators used are preferably inorganic and/ororganic peroxides, inorganic and/or organic hydroperoxides, barbituricacid derivatives, malonylsulphamides, protic acids, Lewis or Broenstedacids and/or compounds which release such acids, carbenium ion donorssuch as methyl triflate or triethyl perchlorate, for example, or amixture, of these compounds, and coinitiator or coinitiators used arepreferably tertiary amines, heavy metal compounds, more particularlycompounds of groups 8 and 9 of the Periodic Table (“iron group andcopper group”), compounds having ionogenically bonded halogens orpseudohalogens, such as quaternary ammonium halides, for example, weakBroensted acids such as, for example, alcohols and water or a mixture ofthese compounds.

In one particularly simple embodiment the instrument for applying theinfiltrant (application aid) to the tooth is coated or impregnated withthe activator.

In a further embodiment a first component comprises monomers and asinitiators, salts of CH-acidic compounds such as barbituric acidderivatives, and a second component comprises monomers and an activatingcomponent, preferably a more strongly acidic acid than the CH-acidiccompound.

In one particularly simple embodiment an instrument for applying theinfiltrant (application aid) to the tooth comprises canulas containing amixing chamber and/or mixing elements.

The infiltrant may comprise stabilizers. Preference is given to UVstabilizers. Suitable UV stabilizers are known to the skilled worker;cited here by way of example are Chimasorb® and Tinuvin® (Ciba).

The infiltrant may comprise (nonpolymerizable) solvents. Preference isgiven to solvents of medium volatility, such as, for example, alcohols,relatively high molecular weight ketones and ethers, and also esters,and so on. Particular preference is given to alcohols, more particularlyethanol, or to solvents having similar evaporation characteristics.

The infiltrant preferably contains less than approximately 20% by mass,more preferably less than approximately 10% by mass, with particularpreference no solvent.

The infiltrant may comprise at least one fluorescent dye and/or colorpigments, in order to improve the appearance and/or adapt it to thedental enamel. Suitable fluorescent colorants are known to the skilledperson and described in US 2004/017928 A1, for example. The infiltrantmay comprise other colorants, especially for the production of differenttooth colors. The infiltrant may comprise color-changing dyes whichindicate the infiltrated lesion and change color to indicate the curingof the infiltrant. Preferably the dye becomes colorless after theinfiltrant is cured. The dye may be free-radically reactive.

The color change may also be dependent on other influences, such as onthe pH, for example.

The dye may have adsorptive properties, particularly with respect to thedental enamel, and so accumulates in the upper layer of the lesion. Inthat case it is also possible to see the color change mere readily inthe interdental region.

The dye may have nonadsorptive properties and may penetrate deeply intothe lesion, thereby making it possible, for example, to monitor theinfiltration more effectively.

The infiltrant may comprise thermochromic and/or photochromic additiveswhich indicate the infiltrated region on irradiation with correspondinglight and/or on temperature change.

The infiltrant may comprise contrast agents for the purpose ofX-ray-opacity, preferably organic compounds, as disclosed in EuropeanPatent Application EP 08014437.

The invention further provides for the use of an infiltrant of theinvention to treat and/or prevent carious enamel lesions. Such use mayencompass the following steps:

-   1. removing a thin surface layer of the enamel lesion by etching    agent.-   2. rinsing off the etching agent-   3. drying the lesion with a drying agent-   4. infiltrating the lesion with an infiltrant-   5. removing excesses (optional)-   6. curing the infiltrant-   7. infiltrating the lesion with an infiltrant (optional)-   8. removing excesses (optional)-   9. curing the infiltrant (optional)-   10. polishing the infiltrated lesion surface (optional).

In individual steps of the infiltration method the desired result may beimproved further by application of sound and/or ultrasound.

Preferred etching agents are gels of strong acids such as hydrochloricacid.

Preferred drying agents are toxicologically unobjectionable solventswith a high vapor pressure. Particular preference is given to dryingagents having a vapor pressure which is greater than that of water (23mbar [20° C.]). They are selected, for example, from alcohols, ketones,ethers, esters, etc. Particular preference is given to ethanol.

The drying agent may comprise constituents of the initiator system whichremain in the lesion after the system has evaporated.

The drying agent may comprise a film-former.

The invention additionally encompasses a kit for implementing theinfiltration method. Said kit comprises

-   1. etching agent-   2. drying agent (optional)-   3. infiltrant

The invention is illustrated below with reference to a number ofexamples.

Monomer mixtures were prepared and investigations were carried out intotheir penetration coefficient (PC), through-cure depth, mechanicalbehavior, and adhesive strength (shear bond strength).

The following components were employed:

TEDMA triethylene glycol dimethacrylate E3TMPTA trimethylolpropaneethoxylated with on average 1 EO unit per methylol group and termiallyacrylated MDP 10-methacryloyloxydecyl dihydrogenphosphate CQcamphorquinone EHA ethylhexyl p-N,N-dimethylaminobenzoate BHT2,6-di-tert-butylphenol

Test Methods

Surface Tension

The surface tension of the resins was carried out by means of contouranalysis on a hanging droplet (DSA 10, KRÜSS GmbH). The surface tensionwas measured on newly formed droplets over a time of 30 s, with onevalue being recorded about, every 5 s. For this purpose the resins weredelivered using a fine syringe and the droplet that formed was filmedwith a digital camera. The surface tension was determined from thecharacteristic shape and size of the droplet in accordance with theYoung-Laplace equation. For each resin, 3 measurements were carried outin this way, and their average was reported as the surface tension.

Contact Angle

Each individual measurement was carried out using enamel from bovineteeth. For this purpose, bovine teeth were embedded in a synthetic resinand the enamel surface was wet-polished using a sanding machine (StruersGmbH) with abrasive papers (80, 500 and 1200grades), thereby providingplanar enamel surfaces approximately 0.5×1.0 cm in size for the contactangle measurements. Up until the time of measurement, the enamel sampleswere stored in distilled -water, and prior to measurement they weredried with ethanol and compressed air.

The contact angle was measured using a video contact angle measuringinstrument (DSA 10, KRÜSS GmbH). In this case a drop of the resinmixture was applied to the enamel surface using a microliter syringe,and within a period of 10 s up to 40 individual pictures of the dropletwere taken, under computer control, and the contact angle was determinedby means of droplet contour analysis software.

Through-Cure Depth

The through-cure depths of the resins were determined in accordance withthe “polymerization depth” test of ISO 4049:2000. For this purpose theresins were placed in cylindrical Teflon moulds (5 mm in diameter, 10 mmhigh) and exposed from above using a halogen lamp (Translux EC fromHeraeus Kulzer GmbH) for 15 or 20 s. Immediately after light exposure,the cured specimens were demoulded and were freed from uncured materialusing a plastic spatula. The height of the cured cylindrical cone wasreported as the through-cure depth (TCD).

Dynamic Viscosity

The viscosity of the resins was measured at 23° C. using a dynamicplate/plate viscometer (Dynamic Stress Rheometer, Rheometric ScientificInc.). Measurement took place in steady stress sweep mode with slotsizes of 0.1 to 0.5 mm in the range from 0 to 50 Pa shearing stresswithout preliminary shearing of the resins.

Shear Bond Strength (SBS) Measurements

The adhesion of the infiltrants of the invention was measured bycarrying out shear bond strength (SBS) tests. For this purpose, bovineincisors with their pulp removed beforehand, which had undergonesubsequent storage in 0.5% by weight Chloramin-T solution in water, weresubjected to wet planar grinding on the facing side. Depending on theconditions of the test, the planar enameled surfaces were microabradedusing 15% strength HCl gel by exposure for 2 minutes, or left untreated.Then the infiltrants of the invention or the reference examples wereapplied to the etched enamel surface using a Mirobrush, and left to actfor 240 s. Subsequently the infiltrated area was exposed for 40 s usinga halogen lamp [Translux EC, from Heraeus Kulzer]. A two-piece Teflonmold with a cavity of 3.0 mm in diameter was mounted, and thephotocuring dental composite EcuSphere Shape (ultrafine glass hybridcomposite; DMG) was introduced and exposed for 40 s with a halogen lamp[Translux EC, from Heraeus Kulzer]. The Teflon mold was removed and theadhesive bond was stored in water first for 23 h at 37° C. and then for1 h at 23° C. The bond was subsequently clamped into a mount formeasuring the SBS, and was subjected to measurement in an apparatus fordetermining a force-displacement diagram (Z010, Zwick GmbH, Ulm) at arate of advance of 0.5 mm/min in accordance with ISO/TS 11405:2003“Dental materials—Testing of adhesion to tooth structure”. The resultswere recorded in the form of an average, a standard deviation(expression in brackets), and the sum of the individual measurements(n=6-8).

Description of the preparation of examples and reference examples.

The resins as per table 1 were prepared by stirring of the correspondingcomponents together. For the investigations of through-cure depth, andadhesive strength (shear bond strength), 0.45% or 0.5% by weight of CQ,0.76% or 0.84% by weight of EHA, and 0.002% by weight of BHT were addedto the resin mixtures. All of the mixtures were stirred until they gavean optically clear solution.

TABLE 1 Reference 1 Example 1 Example 2 Reference 2 Example 3 Example 4TEDMA 100 99 90 80 79.2 72 E3TMPTA 20 19.8 18 MDP 1 10 1 10 CQ 0.5 0.50.45 0.5 0.5 0.45 EHA 0.84 0.84 0.76 0.84 0.84 0.76 BHT 0.002 0.0020.002 0.002 0.002 0.002 Viscosity [mPas] 10 8 11.9 12 12.0 17.0 Surfacetension [mN/m] 35.07 35.37 35.12 35.37 35.96 35.63 Contact angle enamel[°] 0.4 0.8 1.7 2.4 1.0 2.1 Penetration coefficient [cm/s] 175 221 148147 150 105 TCD [mm] after 20 s exposure 0 10 10 4.1 10 10 TCD [mm]after 15 s exposure 0 6.4 7.5 3.5 8.04 9.5 SBS measurements [MPa] on 3.8 (0.8) 10.1 (1.8) 12.1 (1.6) 14.7 (1.9) unetched bovine enamel;average n = 8 n = 8 n = 7 n = 6 (SD); number of individual measurementsSBS measurements [MPa] on HCl- 21.0 (1.4) 22.7 (2.4) 24.8 (2.3) 26.5(4.1) etched, bovine enamel; average n = 8 n = 7 n = 8 n = 6 (SD);number of individual measurements

The composition in Table 1 is indicated in parts by weight.

Table 1 shows that the addition even of small amounts of the acidicmonomer MDP leads to a significantly improved through-cured depth. Thecombination of the addition of an acidic monomer MDP and of acrosslinking i monomer having three polymerizable groups (E3TMPTA) leadsto excellent through-cured depths even with a low exposure time.

Furthermore, table 1 shows that the inventive examples exhibit improvedadhesion to HCl-etched bovine enamel. A particular advantage is thedrastically improved adhesion to unetched bovine enamel.

Reference 3 and example 5 (table 2) were produced by adding 5 parts and30 parts, respectively, of MDP to a mixture of 80 parts of TEDMA, 20parts of E3TMPTA, 0.64 part of CQ, 1.06 part of EHA, and 0.003 part ofBHT. The mixtures were protected from light or were exposed only toyellow light; all the measurements were carried out under correspondingconditions in order to rule out unwanted polymerization of the mixture.

TABLE 2 Reference 3 Example 5 TEDMA 55.1 74.7 E3TMPTA 13.8 18.7 MDP 30 5CQ 0.44 0.59 EHA 0.73 1.00 BHT 0.002 0.002 Viscosity [mPas] 38 12Penetration coefficient [cm/s] 46 146 Water absorption [μg/mm³] 103.1(3.2) 68.0 (1.7) Solubility [μg/mm³]  14.1 (1.0)  2.3 (0.5) TCD [mm] 10s 8.2 3.3 15 s 10 10 Color difference (ΔE) 9.9 5.2 SBS [MPa] unetched3.0 (1.0); n = 9 14.9 (5. 0); n = 7

The compositions are indicated in parts by weight (rounded).

In spite of a relatively low initiator fraction, reference 3 showed anincrease in through-cured depth (TCD) after 10 s. The high fraction ofMDP resulted in a penetration coefficient of less than 50 cm/s. The bondstrength (SBS) was only 3 MPa. Reference 3 also exhibited waterabsorption, water solubility and/or color stability which was such as tomake the composition disadvantageous for use in accordance with theinvention. The water absorption and water solubility of the compositionwithout addition of MDP, which were likewise measured for purposes ofcomparison, were 60.8(2.7) and 1.5 μg/mm³, respectively. The waterabsorption and water solubility were determined in accordance with ISO4049:2000, the specimens made from the stated resins being cured by2×180 s exposure in a photopolymerization apparatus (Heraflash).

The color stability was determined by curing specimens made from thestated resins by 2×180 s exposure in a photopolymerization apparatus(Heraflash) in accordance with ISO 4049:2000 (color stability) and thenstoring them in demineralized water in the dark at 60° C. At the startand after defined intervals of time, the color of the specimens wasmeasured using an electronic colorimeter in accordance with a CIEstandard. The color differences (deviations in the L, a, b values) ofthe specimens are reported in ΔE units. The greater the ΔE value, thegreater the color change of the specimen.

1. An infiltrant for dental application, comprising crosslinkingmonomers, which has a penetration coefficient PC>50 cm/s and comprises0.05%-20% by weight of acid-group-containing monomers.
 2. The infiltrantas claimed in claim 1, wherein the amount of acid-group-containingmonomers is 0.1% to 15%, preferably 0.2% to 10%, more preferably 0.5% to5%, more preferably 0.5% to 2% by weight.
 3. The infiltrant as claimedin claim 1, wherein the acid-group-containing monomers containphosphoric and/or phosphonic acid groups.
 4. The infiltrant as claimedin claim 1, wherein the acid-group-containing monomers contain one ortwo, preferably one, polymerizable group(s).
 5. The infiltrant asclaimed in claim 1, wherein the acid-group-containing monomers areacrylates, methacrylates, acrylamides and/or methylacrylamides.
 6. Theinfiltrant as claimed in claim 1, which has a penetration coefficientPC>100 cm/s.
 7. The infiltrant as claimed in claim 1, wherein thefraction of crosslinking monomers having two polymerizable groups is99.8% to 50%, preferably 99.5% to 60%, more preferably 99% to 60%, morepreferably 99% to 70% by weight.
 8. The infiltrant as claimed in claim1, wherein the crosslinking monomers having two polymerizable groups areesters of acrylic or methacrylic acid and are preferably selected fromthe group consisting of allyl methacrylate; allyl acrylate; PRDMA,1,3-propanediol dimethacrylate; BDMA, 1,3-butanediol dimethacrylate;BDDMA, 1,4-butanediol dimethacrylate; PDDMA, 1,5-pentanedioldimethacrylate, NPGDMA, neopentyl glycol di-methacrylate; HDDMA,1,6-hexanediol dimethacrylate; NDDMA, 1,9-nonanediol dimethacrylate;DDDMA, 1,10-decanediol dimethacrylate; DDDDMA, 1,12-dodecanedioldimethacrylate; PRDA., 1,3-propanediol diacrylate; BDA, 1,3-butanedioldiacrylate; BDDA, 1,4-butanediol diacrylate; PDDA, 1,5-pentanedioldiacrylate; NPGDA, neopentyl glycol diacrylate; HDDA, 1,6-hexanedioldiacrylate; NDDA, 1,9-nonanediol diacrylate; DDDA, 1,10-decanedioldiacrylate; DDDDA, 1,12-dodecanediol dimethacrylate; EGDMA, ethyleneglycol dimethacrylate; DEGDMA, diethylene glycol dimethacrylate; TEDMA,triethylene glycol dimethacrylate; TEGDMA, tetraethylene glycoldimethacrylate; EGDA, ethylene glycol diacrylate; DEGDA, diethyleneglycol diacrylate; TEDA, triethylene glycol diacrylate; TEGDA,tetraethylene glycol diacrylate; PEG200DMA, polyethylene glycol200dimethacrylate; PEG300DMA, polyethylene glycol 300 dimethacrylate;PEG400DMA, polyethylene glycol 400 dimethacrylate; PEG600DMA,polyethylene glycol 600 dimethacrylate; PEG200DA, polyethylene glycol200 diacrylate; PEG300DA, polyethylene glycol 300 diacrylate; PEG400DA,polyethylene glycol 400 diacrylate; PEG600DA, polyethylene glycol 600diacrylate; PPGDMA, polypropylene glycol dimethacrylate; PPGDA,polypropylene glycol diacrylate; NPG (PO) 2DMA, propoxylated (2)neopentyl glycol dimethacrylate; NPG (PO) 2DA, propoxylated (2)neopentyl glycol diacrylate; bis-MA, bisphenol A dimethacrylate;bis-GMA, bisphenol A glycerol dimethacrylate; BPA (EO) DMA., ethoxylatedbisphenol A dimethacrylate (EO=1-30); BPA (PO) DMA, propoxylatedbisphenol A dimethacrylate (PO=1-30); BPA (EO) DA, ethoxylated bisphenolA diacrylate (EO=1-30); BPA (PO) DA, propoxylated bisphenol A diacrylate(PO=1-30) ; BPA (PO) GDA, propoxylated bisphenol A glycerol diacrylate;UDMA, diurethane dimethacrylate; TCDDMA,tricyclo[5.2.1.0]decanedimethanol dimethacrylates; TCDDA,tricyclo[5.2.1.0]decanedimethanol diacrylates; EBA,N,N′-ethylenebisacrylamide; DHEBA,N,N′-(1,2-dihydroxyethylene)bisacrylamide; DEPBA,N,N′-diethyl(1,3-propylene)bisacrylamide; TMHMBMA,N,N′-(2,2,4-trimethylhexamethylene)bismethacrylamide; andbis[2-(2-methylacrylamino)ethoxycarbonyl]hexamethylenediamine.
 9. Theinfiltrant as claimed in claim 1, which further comprises monomershaving at least three polymerizable groups, the fraction of crosslinkingmonomers having at least three polymerizable groups being preferably 10%to 50% by weight, more preferably 10% to 30% by weight, the crosslinkingmonomers having at least three polymerizable groups preferably having adistance between crosslinking points of at least 7bond lengths, morepreferably not more than 50 bond lengths, more preferably 10 to 30 bondlengths, more preferably 11 to 21 bond lengths, and more preferably thefraction of crosslinking monomers having at least three polymerizablegroups and a distance between crosslinking points of less than 10 bondlengths, based on the total mass of the monomers, being less than 20% byweight, preferably less than 10% by weight, more preferably less than 5%by weight.
 10. The infiltrant as claimed in claim 9, wherein thecrosslinking monomers having at least three polymerizable groups havethe formula belowR¹[X_(k)R² _(l)Y_(m)]_(n) having the following definitions: R¹ is alinear or branched hydrocarbon having 3-24 C atoms, comprising alkyl,cycloalkyl or aryl; optionally containing O, N, Si, S, P as heteroatoms,examples being siloxane and, or cyclosiloxane and/or carbosilane and/orcyclocarbosilane and/or, in particular, ether groups or polyethergroups, polyester groups, polysiloxane groups or polycarbosilane groups;optionally substituted by hydroxyl and/or carbonyl and/or halogen(preferably fluorine) and/or ammonium-alkylene groups and/or siloxaneand/or cyclosiloxane and/or carbosilane and/or cyclocarbosilane; R² is alinear or branched hydrocarbon having 1-16 C atoms, comprising alkyl,cycloalkyl or aryl; optionally containing O, N, Si, S, P as heteroatoms,examples being siloxane and/or cyclosiloxane and/or carbosilane and/orcyclocarbosilane and/or, in particular, ether groups or polyethergroups, polyester groups, polysiloxane groups or polycarbosilane groups;optionally substituted by hydroxyl and/or carbonyl and/or halogen(preferably fluorine) and/or ammonium-alkylene groups and/or siloxaneand/or cyclosiloxane and/or carbosilane and/or cyclocarbosilane; X is alinking group identically or differently selected from an ether group,carbonyl group, ester group, amide group, urethane group or urea group;Y is a group identically or differently containing a polymerizabledouble bond and/or a ring-openingly polymerizable group and/or a thiolgroup and/or an epoxide group and/or a vinyl, preferably (meth)acrylateand/or (meth)acrylamide; k is 0 or 1; l is 0 or 1; m is a least 1; n isat least 1; and m×n is at least
 3. 11. The infiltrant as claimed inclaim 9, wherein the crosslinking monomers having at least threepolymerizable groups are selected from the group consisting of TMPTMA,trimethylolpropane trimethacrylate; TMPTA, trimethylolpropanetriacrylate; DTMPTA, ditrimethylolpropane tetra(meth)acrylate; diPENTA,dipentaerythritol penta(meth)acrylate; GPTA, propoxylated glyceryltri(meth)acrylate; DPEHA, dipentaerythritol hexa(meth)acrylate; andethoxylated trimethylolpropane tri(meth)acrylate; preferably selectedfrom the group consisting of propoxylated, glyceryl tri(meth)acrylate;ethoxylated trimethylolpropane trimethacrylate, ethoxylatedtrimethylolpropane triacrylate, propoxylated trimethylolpropanetrimethacrylate, propoxylated trimethylolpropane triacrylate,ethoxylated pentaerythritol trimeth-acrylate, ethoxylatedpentaerythritol triacrylate, ethoxylated pentaerythritoltetramethacrylate, ethoxylated pentaerythritol tetraacrylate,ethoxylated dipentaerythritol trimethacrylate, ethoxylateddipentaerythritol tetramethacrylate, ethoxylated dipentaerythritolpentamethacrylate, ethoxylated dipentaerythritol hexamethacrylate,ethoxylated dipentaerythritol triacrylate, ethoxylated dipentaerythritoltetraacrylate, ethoxylated dipentaerythritol pentaacrylate, ethoxylateddipentaerythritol hexaacrylate, propoxylated pentaerythritoltrimethacrylate, propoxylated propoxylated pentaerythritoltrimethacrylate, propoxylated tetramethacrylate, propoxylatedpentaerythritol tetraacrylate, propoxylated dipentaerythritoltrimethacrylate, propoxylated dipentaerythritol tetramethacrylate,propoxylated, dipentaerythritol pentamethacrylate, propoxylateddipentaerythritol hexamethacrylate, propoxylated dipentaerythritoltriacrylate, propoxylated dipentaerythritol tetraacrylate, propoxylateddipentaerythritol pentaacrylate and propoxylated dipentaerythritolhexaacrylate.
 12. The infiltrant as claimed in claim 1, having a dynamicviscosity or 50 mPas or less, preferably 30 mPas or less, morepreferably 20 mPas or less.
 13. The infiltrant as claimed in claim 1,containing 20% by weight or less, preferably 10% by weight or less ofsolvent, more preferably essentially containing no solvent.
 14. A kitfor preparing an infiltrant as claimed in claim 1, wherein the kitcomprises a first component with monomers and chemically activableinitiators and a second component with activators, the kit preferablyfurther comprising etching agents and/or drying agents.
 15. Theinfiltrant as claimed in claim 1 to treat and/or prevent carious enamellesions.